Project Summary Chronic multisite pain, a major contributor to functional loss in older adults, impacts both cognition and motor function, and increases fall risk in older persons. Tai Chi which holistically integrates physical and cognitive functions offers the possibility not only of alleviating pain but also improving attention and mobility in the many older adults who have multisite pain. This proposed full-scale randomized controlled Tai Chi trial is a direct extension of our previous work examining chronic pain, attention demands, mobility and falls in the older population, and is built on our National Institute on Aging-supported Tai Chi feasibility and acceptability pilot study among older adults with multisite pain and risk for falls (NIH R21 AG043883). The goal of this single- blinded randomized controlled trial is to examine the effects of a 12-week Tai Chi intervention on chronic pain, cognition, mobility, fear of falling, and fall rates in older adults with multisite pain and fall risk. We will measure pain severity, pain interference, pain-related biomarkers, cognition, single-task and dual-task gait, and fear of falling, pre- and post-intervention in 250 older adults (Tai Chi: N=125, and light physical exercise control: N=125). We will also measure rates of total and injurious falls during the intervention and the 6-month follow- up period after the intervention. We have 2 primary specific aims: Aim 1 is to examine the effects of Tai Chi on pain symptoms in older adults with multisite pain. We hypothesize that older adults in the Tai Chi intervention will have less pain, measured as pain severity and interference, than those in the light physical exercise control group. Aim 2 is to examine the effects of Tai Chi on rate of falls and fear of falling in older adults with multisite pain. We hypothesize that older adults in the Tai Chi intervention will have fewer falls (during the intervention and the 6-month follow-up period) and less fear of falling than those in the light physical exercise control group. We have 3 discovery aims: Aim 3 is to examine the effects of Tai Chi on pain-related biomarkers in older adults with multisite pain. We hypothesize that older adults in the Tai Chi intervention will have greater reductions in levels of pain-related biomarkers, than those in the light physical exercise control group. Aim 4 is to examine the role of improvement in chronic pain in the reductions of fall rates by Tai Chi in older adults with multisite pain. We hypothesize that the reductions in fall rates are dependent on the improvement in pain symptoms in older adults with chronic multisite pain. Aim 5 is to examine the roles of improvements in cognition and mobility in the reduced of fall rate by Tai Chi in older adults with multisite pain. We hypothesize that the reduced fall rate is mediated by changes in cognition and mobility in older adults with chronic multisite pain. The results of this study will provide a foundation to establish the clinical significance of Tai Chi in the management of chronic multisite pain and to explore the mechanisms through which Tai Chi improves pain symptoms and lowers fall rates in at-risk older adults.